Aluminum is the most important non-ferrous metal of the modern age. The properties of its alloys depend on their composition and microstructure. By adding alloying elements, we can significantly enhance the usability of aluminum. It is categorized into several groups based on the main alloying elements. Metals with low density, such as lithium and calcium, are added to aluminum to reduce its density and increase the strength of the alloy. Due to the rapid development of metallic materials and applications, there is a need to research new advanced alloys with better mechanical properties.
In this thesis, we thermodynamically characterized an Al-Ca-Li alloy system. First, we prepared the alloy by alloying technically pure aluminum with lithium and calcium, then cast it into a steel measurement cell and performed a simple thermal analysis. From the cooling curve, we determined the liquidus temperature, solidus temperature, and two eutectic temperatures. We then continued with the determination of the alloy composition using X-ray fluorescence analysis. Differential scanning calorimetry was conducted to determine the melting and solidification enthalpies of the present phases and characteristic temperatures. Thermodynamic calculations were also performed to illustrate isopleth diagrams and Scheil diagrams. The sample was observed using an electron microscope to define the phases in the alloys.
The results showed that calcium formed an eutectic (α-Al + Al4Ca) with aluminum and also indicated that aluminum combined with iron to form a phase Al13Fe4.
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